


Bouncing Baby Blaster

by damnedxfate



Category: Undertale (Video Game)
Genre: Alternate Universe - Echotale (Undertale), Alternate Universe - Gaster Blaster (Undertale), Alternate Universe - Swapfell (Undertale), Birth, Ectobiology, M/M, Male Pregnancy, Multiverse Convergence, Post-Undertale Pacifist Route, Pregnancy, Swapfell Papyrus (Undertale), Swapfell Sans (Undertale), first time writing birth, hard pregnancy, let me know if a tag is missing, low constitution, reference to sex, semi-graphic birth, skelepreg
Language: English
Status: Completed
Published: 2019-07-15
Updated: 2019-07-15
Packaged: 2020-06-28 14:31:07
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,217
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/19814254
Author URL: https://archiveofourown.org/users/damnedxfate/pseuds/damnedxfate
Summary: Continuation of a mini story in my week long drabble event.What happens after Blaster Slim mates with Black and breeds him?A story leading up to and the birth of their child.





	Bouncing Baby Blaster

**Author's Note:**

  * For [MuchCookiez](https://archiveofourown.org/users/MuchCookiez/gifts).



> Commission for thycutterzofmuchcookiez on tumblr.
> 
> This is my first time writing birth or in depth pregnancy but I hope you guys like it.

The moderately sized master bedroom looked like something right out of a romance novel. The clean cream colored walls and black marble counter-top reflecting the warm firelight from dozens of small tea lights. Red and pink rose petals rested on every available surface from the floor to delicately floating atop the sweet smelling bath water.   
Rejuvenating oils had been infused into the warm rinse under a carpet of white bubbles all resting atop a diminutive skeleton.   
  
Black, said skeleton, was reclining over the back of the tub and up to a moment ago had reached inner peace until his very round mid-section rumbled its displeasure.    
  
Black was very obviously 9 months pregnant. Despite the tub being deep the well of his ecto-flesh cleared the water line like an island rising from the ocean’s depth. He had been rubbing the medical oils over his bump when a demanding gurgle had split the relative silence of the bathroom.   
  
The soul ling was hungry and there was no conceivable way Black could get out of the tub on his own without help or a grand struggle. This could lead to one of two things but both loud and glass shattering.   
Black’s already delicate temper had reaching new heights with the pregnancies hormonal imbalance and would cry at the drop of a hat or rage over the silliest of reasons.    
His doctor, Green the Papyrus-Gaster fusion of Echotale, had warned him to try and control himself as best he could because the pregnancy was delicate as it was.   
  
While Black and Slim had wanted a baby and were deep in conversation over preparing for one, Slim rut hit. Instincts deemed the environment favorable and forced him into his secondary form, that they now knew was called Blaster mode, to ensure fertilization through high magical output and stronger stats on the off chance there was a challenger.    
Slim had taken as many precautions as he could to guarantee Black would kindle on the first try so to not stress the smaller skeleton through several painful, from the new greater size difference, matings; there had still been an unpredictable outcome.    
  
Advanced 3D medical scans showed the baby’s skeletal structure from inside the womb. Small nubs that would one day become majestic horns growing from a slightly elongated skull frame. Tiny clenched hands and curled up legs showing a second joint for both bipedal and quadrupedal walking. Rotating the screen showing the precursor of a tail forming at the base of the spine.    
Their unborn child had inherited not only the Blaster gene but the Blaster form as well.    
Dr.Green assured them that more than likely once the babe was a bit older the child would be able to switch forms but as of now they were locked in and the pregnancy was even more fragile.   
  
Black with one Hp, smaller even than Blue who already had trouble birthing his own child a few months earlier, things could get messy.    
  
Which left the short tempered skeleton still stuck in his predicament. On his back, in a slippery water filled tub, hungry.   
  
“Slim! I require assistance!” Black called out loudly. Their house might not be that big but it was well insulated and noise did not carry very well. He waited a moment for a reply before calling out again, “SLIM! GET ME OUT OF THIS TUB...PLEASE”   
  
This time there was a reply from somewhere in the house, “just a minute!.”    
Black’s stomach chose that moment to roar louder, echoing off the bathroom tiles, and give an almighty cramp. The pain, hunger, and his fragile mood became an amalgamation that Slim often described as “hangry” these days. Black’s default mood. The baby wanted magic and food now and Black had no patience for waiting.   
  
With a foot he blindly searched for the drainage plug and pulled it out once he found it. Huffing he gripped the sides of the tub and began to rock back and forth. He had quickly found out this was the easiest way to sit up with his large belly. Like a turtle stuck on it’s back, he rolled side to side until he could pull himself into a sitting position and a partial crouch over the lip of the tub. He sat momentarily out of breath from the exercise, embarrassed over his “weakness”- not that you can exercise when you are imitating a whale- but grabbed the towel enough to pat most of the water off.    
No reason to make a mess even if he wasn’t the one cleaning it.    
  
Trying his best to wrap the star printed towel around himself, but failing over the bump of his stomach that stood quite proudly out between the ends, he waddled his way out of the room. Black did have to pause a moment to hiss in annoyance and scrape some petals off his heel but made it out the door and into the carpeted hallway. The slight cushioning a miracle on his sore ankles.    
  
The trek from the bathroom to the kitchen wasn’t all that long. Their house sensibly sized with a decent layout for a two bedroom. The second bedroom used to be his office but had been re-purposed as a baby room not that Black had any intention for their child to sleep anywhere but right besides him where it’s safest.    
He still arrived at the kitchen archway huffing, hungry and angrier. He should not have been walking that damnit. Logically, somewhere in the back of his mind, he knew he was being overly emotional and projecting, it wasn’t Slim’s fault, Black could see he was on the phone with someone important. It was hard not to recognize Dr. Green’s smooth, accented baritone over the receiver but it wasn’t enough to stop incoming tantrum.   
  
Black marches, to the best of his ability, up to Slim with an angry growl, “How dare you! You leave me in that tub like a pig in a wallow with no way out and don’t come when I call you?” Never mind that Black had picked that tub. “I am pregnant with your child and you don’t have the decency to take that MOBILE FUCKING PHONE AND BRING ME A PIT DAMNED SNACK YOU BA-” Black stopped his tirade when he felt a stream of warm liquid make its way down his thighs.   
His first thought was, ‘ _ but I patted myself dry _ ’ but the trickle became a torrent that splattered the kitchen tile between, on and around his feet. This could only mean one thing.   
  
“I think my water just broke…” Black shockingly whispered. Slim on his part stared at the increasingly growing puddle in stupefied horror until Dr. Green yelled at them over the phone to get to over there now. He would begin prepping the birthing room.    
  
Slim dropped the phone and swooped forward with a yelp to scoop Black into his arms and took off into a sprint out and then around the house to their shed where the machine lay. His mantra of ‘oh shits’, ‘ oh fucks’ and high pitched squawks of ‘IMMA BE A DADDY’ bounced off the shed walls followed by the sharp whine of the multi-dimensional transporter booting up.   
  
Black was staring dumbfounded at the swirling colors on his rounded ecto-flesh. He was about to give birth! Soon he would get to hold his baby in his arms and be a mom.   
  
He was terrified of the middle part.   
  
This was going to hurt...a lot.

* * *

  
“FUCK! HAAAAAH GET THEM OUT!” Black screamed loudly. He had been warned that giving birth was painful but no words could prepare him for this. It was beyond excruciating. Nothing in his life had ever hurt more than what was happening now. Not fighting for his life, not his ‘sessions’ with the Mad Queen, not even the conception of their child when he was bent in half by his transformed brother.  
It felt like his body was being pulled from the inside out - which wasn’t that far from the truth, actually.   
  
Once they arrived at Dr. Green’s, they were directed to the birthing room where Slim was prompted to place Black on the bed.   
There would be no nurses in case the stressful environment triggered Slim’s protective instincts. He would recognize Green as a healer but the nurses may be collateral. Same for the stirrups on the off chance Black became violent or hurt himself in his struggles.  
His legs were spread and hooked onto the two stirrups that pulled him up and open, exposing him to the Doctors piercing eyes.   
This wouldn’t be his first time helping one of his own or his brother’s counterparts but it certainly would be one of his most challenging.   
  
Black’s privates were wiped down and Slim was directed to disinfect his hands along side the Doctor. They both pulled on a pair of gloves, and took their positions. Slim at Black’s side and Dr. Green between spread thighs.   
Bacteria didn’t harm monsters the way it harmed humans but the infant's system would be weak and sensitive right after birth.   
  
Which would be very soon by how dilated Black was, almost at 10CM. Thank the stars. Black’s low HP would never be able to handle anything longer. They would need to time each push when a contraction hits. The purple ecto-flesh shaking and clenching with each clench.   
  
“I need you to push when the next contraction arrives Black. You must press down and help your infant out.” Dr. Green calmly orders. “Slim hold his hand and speak to him. Keep him calm or things will over complicate.” He checks his watch and times each clench. They were getting closer and closer together.   
Finally, it’s time. “Alright Black. Push, you can do this”  
  
Black wails and follows his Doctor’s order, Pushing downward when he feels the telltale pressure. The healing magic coating Dr. Green’s hands thankfully aiding in numbing the area, the creeping warmth crawling up his spine and helping to release some of the force.  
Black takes the offered hand and squeezes with each push.   
“It HURTS! Get them out of m-me! fuck pl-HAH please!” Black was sobbing. He wanted to kick his legs but they were held fast, he wanted to punch and claw and break but if he lets go of Slim or the bedside he would fall or fly or shatter from the agony. Slim kept up a constant litany of praise and encouragement. He could see and feel his mate struggling.  
  
“I see the head, Black. Your baby is almost here. Just a few hard pushes and you’ll be holding them in your arms” Dr. Green attempts to motivate Black as much as he could. But he couldn’t split his time anymore then he was already. His main focus was on getting the baby out safely.   
  
“I ca-can’t. Make it stop Papy” Black weeps shaking his head back and forth. He’s limp now, struggling to give the last few pushes. He can’t feel anything beyond the horrible weight slung low on his body. When he was of clear mind Black would later swear that he could feel the shoulders of their unborn child knocking against the inner side of his pubic symphysis, stretching the cartilage near its breaking point.   
  
Slim was not going to pick one or the other. He was not going to lose his mate or his child because he had no damn control. Slim climbs on the bed behind Black despite Dr. Green’s protest. He pulls Black against his chest and sets his hands, fingers spread wide, on either side of Black’s belly.  
  
“You’re Sans the malevolent and powerful. You are the pits damned Captain of the Royal Guard of Swapfell. You are fucking amazing and going to be the best mother our baby could ever have. Now push damnit! Push with everything you have Sans!” Slim screams. He pulses his SOUL brightly, his magical force warping the air around them; charging it with static. He might not be a doctor but he **shoves** green magic into his hands and into Black.  
Slim lets out a scream the same time Black does. The overhead light bulbs shatter, cabinets rattle and for a moment the world hangs weightless but the finally baby slides out into the Doctor’s hands. The room is completely silent beyond Black’s heavy whimpering breathes.   
  
“He’s not crying, why isn’t he crying? PAPY WHY ISN’T HE CRYING?!” Black says demanding. All the books had said his baby was supposed to cry! Why weren’t they crying?!  
  
“Weh..we-weeeeeh weehh!”  
  
Maybe it was the magic that pushed them out so strongly the infant was left stunned. Maybe they just wanted a moment before announcing themselves. Either way the little one had begun to cry softly. Tiny, sharp fingers attached to equally small fist began to wave in the air.   
Dr. Green cleans the excess magic off quickly and efficiently before the babybones is placed into Black’s reaching arms.   
  
“Look at them Papy” Black whispers weakly. Their baby was finally here and he was-  
  
“Perfect” Slim finishes Black’s thought. Their baby was perfect. Slim held his mate and child close. It was like the world was finally right for them. Slim entwined his fingers with Black’s over their child and drew his mate into a loving kiss. 

**Author's Note:**

> Kudos and comment if you enjoyed~


End file.
